These lecture notes provide a self-contained introduction to regularity theory for elliptic equations and systems in divergence form. After a short review of some classical results on everywhere regularity for scalar-valued weak solutions, the presentation focuses on vector-valu…
Abstract theorems of existence, uniqueness and regularity of the solution are proved for a differential equation whose solution takes its values in a sequence of Banach spaces called a Banach scale. The abstract theorems are then applied to obtain existence, uniqueness and regul…
Let [script lowercase]f be any analytic function defined in a neighborhood of the non-empty set [italic]E and let [script]S([italic]E) denote the set of all operator having spectrum included in [italic]E. In this paper the closure and interior of the set [script lowercase]f([scr…
Let [script lowercase]f be any analytic function defined in a neighborhood of the non-empty set [italic]E and let [script]S([italic]E) denote the set of all operator having spectrum included in [italic]E. In this paper the closure and interior of the set [script lowercase]f([scr…
We undertake a systematic study of cyclic phenomena for composition operators. Our work shows that composition operators exhibit strikingly diverse types of cyclic behavior, and it connects this behavior with classical problems involving complex polynomial approximation and anal…
This memoir addresses linear differential equations, asymptotic expansions, and analytic functions.
Introduction Preliminaries on analytic functionals and hyperfunctions Appendix on good compact sets Analytic functionals as boundary values Nonlinear Paley-Wiener theory Strong boundary values Strong boundary values for the solutions of certain partial differential equations Com…
